Hi all,
I've been doing wireless simulations these days. I want to show NAM to my
colleagues to help them to better know about how RTS/CTS reduce the chance
of collisions. But I found NAM doesn't display the packet dropped because of
collisions. Why? Here is a line of the trace file and the NAM trace file for
a packet dropped because of collision:
Trace File Info:
d -t 2.267517062 -Hs 2 -Hd -2 -Ni 2 -Nx 700.00 -Ny 200.00 -Nz 0.00 -Ne
-1.000000 -Nl MAC -Nw COL -Ma 5fe -Md 2 -Ms 0 -Mt 0
NAM Trace File Info:
d -t 2.267517062 -s 2 -d -1 -p RTS -e 44 -c 2 -a 0 -i 0 -k MAC
Why doesn't NAM display this dropping action?
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And to be specific, following is my TCL scripts.
set opt(RTS) 1
set opt(Time) 20
# ======================================================================
# Default Script valions
# ======================================================================
set val(chan) Channel/WirelessChannel ;#Channel Type
set val(prop) Propagation/TwoRayGround ;# radio-propagation
model
set val(netif) Phy/WirelessPhy ;# network interface type
set val(mac) Mac/802_11 ;# MAC type
set val(ifq) Queue/DropTail/PriQueue ;# interface queue type
set val(ll) LL ;# link layer type
set val(ant) Antenna/OmniAntenna ;# antenna model
set val(ifqlen) 50 ;# max packet in ifq
set val(nn) 3 ;# number of mobilenodes
set val(rp) DSDV ;# routing protocol
#set val(rp) DSR ;# routing protocol
set val(x) 1000
set val(y) 500
set val(stoptime) $opt(Time)
# ======================================================================
# Initialize Global Variables
set ns_ [new Simulator]
$ns_ use-newtrace
if {!$opt(RTS)} {
#set RTSThreshold_ to 3000(Larger than any packet size of up level),
so RTS wolud never be sent.
Mac/802_11 set RTSThreshold_ 3000 ;# bytes
puts "Mac/802_11 RTSThreshold_: [Mac/802_11 set RTSThreshold_],
RTS/CTS is turned off"
set tracefd [open col-hidden.tr w]
set namtrace [open col-hidden.nam w]
} else {
set tracefd [open rts-hidden.tr w]
set namtrace [open rts-hidden.nam w]
}
$ns_ trace-all $tracefd
$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)
# set up topography object
set topo [new Topography]
$topo load_flatgrid $val(x) $val(y)
# Create God
create-god $val(nn)
# New API to config node:
# 1. Create channel (or multiple-channels);
# 2. Specify channel in node-config (instead of channelType);
# 3. Create nodes for simulations.
# Create channel #1 and #2
set chan_1_ [new $val(chan)]
set chan_2_ [new $val(chan)]
$ns_ node-config -adhocRouting $val(rp) \
-llType $val(ll) \
-macType $val(mac) \
-ifqType $val(ifq) \
-ifqLen $val(ifqlen) \
-antType $val(ant) \
-propType $val(prop) \
-phyType $val(netif) \
-topoInstance $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace ON \
-movementTrace OFF \
-channel $chan_1_
set node_(0) [$ns_ node]
set node_(1) [$ns_ node]
set node_(2) [$ns_ node]
$node_(0) random-motion 0
$node_(1) random-motion 0
$node_(2) random-motion 0
#
# Provide initial (X,Y, for now Z=0) co-ordinates for mobilenodes
#
$node_(0) set X_ 500.0
$node_(0) set Y_ 200.0
$node_(0) set Z_ 0.0
$node_(1) set X_ 300.0
$node_(1) set Y_ 200.0
$node_(1) set Z_ 0.0
$node_(1) label hidden_to_node2
$node_(2) set X_ 700.0
$node_(2) set Y_ 200.0
$node_(2) set Z_ 0.0
$node_(2) label hidden_to_node1
for {set i 0} {$i < $val(nn)} {incr i} {
$ns_ initial_node_pos $node_($i) 30
}
# Setup traffic flow between nodes 0 and 1
# TCP connections between node_(0) and node_(1)
set tcp1 [new Agent/TCP]
$tcp1 set class_ 2
set sink1 [new Agent/TCPSink]
$ns_ attach-agent $node_(1) $tcp1
$ns_ attach-agent $node_(0) $sink1
$ns_ connect $tcp1 $sink1
set ftp1 [new Application/FTP]
$ftp1 attach-agent $tcp1
$ns_ at 0.1 "$ftp1 start"
# Setup traffic flow between nodes 0 and 2
# udp connections between node_(0) and node_(2)
#set udp [new Agent/UDP]
#set null [new Agent/Null]
#$ns_ attach-agent $node_(2) $udp
#$ns_ attach-agent $node_(0) $null
#$ns_ connect $udp $null
#set cbr [new Application/Traffic/CBR]
#$cbr attach-agent $udp
#$ns_ at 0.1 "$cbr start"
set tcp2 [new Agent/TCP]
$tcp2 set class_ 2
set sink2 [new Agent/TCPSink]
$ns_ attach-agent $node_(2) $tcp2
$ns_ attach-agent $node_(0) $sink2
$ns_ connect $tcp2 $sink2
set ftp2 [new Application/FTP]
$ftp2 attach-agent $tcp2
$ns_ at 0.1 "$ftp2 start"
#
# Tell nodes when the simulation ends
#
for {set i 0} {$i < $val(nn) } {incr i} {
$ns_ at $val(stoptime) "$node_($i) reset";
}
$ns_ at $val(stoptime) "puts \"FINISHED! NS EXITING...\" ; $ns_ halt"
$ns_ at $val(stoptime) "stop"
proc stop {} {
global ns_ tracefd namtrace
$ns_ flush-trace
close $tracefd
close $namtrace
}
puts "Starting Simulation..."
$ns_ run
